Function transformCss

build-system/tasks/css/jsify-css.js:140–152

* @param {string} contents * @param {string} hash * @param {string=} opt_filename * @return {Promise }

(contents, hash, opt_filename)

 * @return {Promise<CssTransformResultDef>}
 */
async function transformCss(contents, hash, opt_filename) {
  if (!transformCache) {
    transformCache = new TransformCache('.css-cache');
  }
  const cached = transformCache.get(hash);
  if (cached) {
    return cached;
  }

  const transformed = transform(contents, opt_filename);
  transformCache.set(hash, transformed);
  return transformed;
}

/**
 * @param {string} contents